CONDENSACION ALDOLICA CRUZADA PDF

CONDENSACION ALDOLICA CRUZADA PDF

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September 13, 2020

como nucleofilo en el carbono del benzaldehído, realizando una reacción de condensación de Claisen-Schmidt (tipo de condensación aldolica cruzada). Particulares ○ Efectuar una condensación aldólica cruzada. ○ Obtener un producto de uso comercial. Diferencia entre una condensación aldólica cruzada y. Específicos Efectuar una condensación aldólica cruzada. Determinar el rendimiento de la reacción realizada y el punto fusión del producto obtenido.

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The method proposed in Japanese Patent Publication No.

Masters and doctoral program in Chemical Sciences

A process for the decomposition of polyhydric alcohols in the synthesis of high-boiling by-products formed. The present invention has been accomplished based on this finding. The purity of TMP obtained was After removing the component and high boiling inorganic salt of crude TMP, the resultant TMP distillate is subjected to a heat treatment under acidic conditions. Ejemplo comparativo 2 Comparative Example 2. Ejemplo comparativo 3 Comparative Example 3. Aldklica, an object of the present invention to provide an industrially advantageous method for producing a highly pure TMP from a crude TMP obtained by a reaction between NBAL and formaldehyde in the presence of a basic catalyst in a two-phase condensation aldol and a subsequent crossed Cannizzaro reaction.

The reaction was complete after 0.

Condensação de Claisen – Wikipédia, a enciclopédia livre

The liquid reaction mixture from the two-stage process contains a formic acid salt formed during the crossed Cannizzaro reaction.

With such heat treatment, the component hardly removable from TMP by distillation is thermally decomposed or chemically combines to form an easily removable component of TMP by distillation. Sin embargo, de manera perjudicial el color fundido del TMP final fue tan elevado como Particularly, MDF, which is quite difficult to remove by normal distillation becomes easily removable components by the treatment of the invention, thus enabling to obtain a highly pure TMP.

The aldol condensation and the subsequent crossed Cannizzaro reaction may be carried out in the presence of water in an amount of 2 to 20 times by weight of NBAL. In the method known in the art, the liquid reaction mixture is distilled after removing most of the formic acid salt by a solvent extraction or a hot filtration after condensing and TMP distillate resulting crude is rectified to obtain thereby a final TMP with a high purity.

The content of the remaining formaldehyde in the final TMP was 1 ppm. Por tanto, se produce a escala industrial de manera ventajosa un TMP sumamente puro utilizable como materia prima para resinas curables con ultravioleta. The Japanese Patent Publication No.

Method for producing a trimethylolpropane TMP highly pure comprising the steps of: The solvent for the extraction may include ketones such as methyl ethyl ketone and methyl isobutyl ketone, aldehydes such as NBAL, also serving as material of alcohols such as isobutyl alcohol and isopropyl alcohol, and esters such as butyl acetate starting, and are typically used in a total amount of 0.

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In the present invention, it is not necessary to use expensive cation exchange resins, etc. Ejemplo comparativo 1 Comparative Example 1. Formaldehyde used in the present invention as starting material can be used as an aqueous solution or solid as paraformaldehyde. Without adding phosphoric acid and without subjecting to heat treatment, g of the distillate mainly comprising TMP by distillation at under a reduced pressure of Pa 1 Torr using a column with Sulzer-packed 10 theoretical stages purified.

A method of further purification is described in DD-A These basic catalysts may be used alone or in combination of two or more. To minimize the occurrence of byproducts and increase selectivity of the objective TMP, preferred set the amount of the basic catalyst according to the reaction conditions.

The content of the remaining formaldehyde in the final TMP was 3 ppm.

Thus, a highly pure TMP has not been obtained with conventional distillation methods. Then, after further adding The present invention relates to a method of purifying a crude TMP obtained by an aldol condensation and a subsequent crossed Cannizzaro reaction of NBAL of formaldehyde in the presence of a basic catalyst.

Recientemente, el TMP ha empezado a ser ampliamente utilizado y particularmente en el uso como materia prima para resinas curables con ultravioleta, presentando el TMP una pureza superior a la que antes se ha llegado a requerir.

Condensação de Claisen

Purification of propylene oxide using an aqueous acetone extractive distillatin agent. A process for obtaining trimethylolpropane-enriched product streams from the secondary streams of trimethylolpropane. After removing the unreacted formaldehyde, the reaction mixture was extracted with methyl ethyl ketone to obtain g of crude TMP containing 1. It is known that the condensation products mentioned above are thermally decomposed under acidic conditions publication of Japanese Patent No.

The molar ratio of formaldehyde to be used in the method with NBAL is 3. For an industrial process, the sodium or potassium salts are preferred. In addition, formaldehyde remaining in TMP product is not the completely eliminated by a usual distillation. To completely remove the impurities such as formaldehyde, MDF, etc. Deactivation is carried out by adding the acid to the crude TMP in an amount 0.

Therefore it occurs industrially advantageously a highly pure TMP usable as a raw material for ultraviolet curable resins.

The first stage aldol condensation and the second stage crossed Cannizzaro reaction are usually conducted successively in the same reaction cruuzada, without differentiating from the operational point of view one another. The gas chromatographic analysis showed that the purity of TMP obtained was However, aldollica cast detrimentally final TMP color was as high as In the present invention, as described above, after first removing the inorganic salt such as sodium formate, and the component of high boiling the crude TMP, the treated TMP is subjected to heat treatment under acidic conditions.

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Method for producing highly pure trimethylolpropane. The product mixture from the reaction of NBAL and formaldehyde is separated, if necessary after removing formaldehyde unreacted by condensation in crude TMP and the formic acid salt, obtained as a byproduct during the crossed Cannizzaro reaction condensaclon a solvent extraction or hot filtration after condensing.

Although the condensation products are decomposed aldolida the heat treatment using excess amount of acid, a colored component from high boiling point, which is difficult to remove TMP by distillation component is formed.

File:Cuatro productos reacción aldólica cruzada.svg

In the following examples and comparative examples, the content of the remaining formaldehyde in the final TMP product was determined by acetylacetone method, and the color cast APHA color pattern obtained crzuada to JIS K document 6. Recently, TMP has come to be widely used and particularly in the use as raw material for ultraviolet curable resins, TMP presenting a higher purity to previously reached require.

TMP obtained cruzdaa the reaction between NBAL and formaldehyde in the presence of basic catalyst in the two-stage process of the aldol condensation and the subsequent crossed Cannizzaro reaction contains the impurities hardly removable by distillation.

However, when TMP contains the formic acid salt and the component of high boiling condensation products are decomposed hard by heat treatment in the presence of acid even in an amount equivalent to the amount of formic acid saltleaving obtained this a highly pure TMP mode. However, since TMP after the solvent extraction, the hot filtration, etc. Method for producing a highly pure trimethylolpropane according to claim 1, wherein component removing high boiling point and the inorganic salt is carried out after deactivating sodium formate present in the crude trimethylolpropane, wherein the deactivation is carried out by means of adding an acid to crude TMP in an amount 0.

The basic catalyst is used aldlica an amount of 1. Ejemplo comparativo 4 Comparative Example 4.